the obvious question is, why do we not more frequently use it? The
answer is to be found in the fact that we have formed the habit of
giving up before we create conditions of high efficiency. You will note
that the conditions require long-continued exertion and resolute
persistence. This is difficult, and we indulgently succumb to the first
symptoms of fatigue, before we have more than scratched the surface of
our real potentialities.

Because of the prominent place occupied by fatigue in thus being
responsible for our diminished output, we shall briefly consider its
place in study. Everyone who has studied will agree that fatigue is an
almost invariable attendant of continuous mental exertion. We shall lay
down the proposition at the start, however, that the awareness of
fatigue is not the same as the objective fatigue in the organs of the
body. Fatigue should be regarded as a twofold thing--a state of mind,
designated its subjective aspect, and a condition of various parts of
the body, designated its objective aspect. The former is observable by
introspection, the latter by analysis of bodily secretions and by
measurement of the diminution of work, entirely without reference to
the way the mind regards the work. Fatigue subjectively, or fatigue as
we _feel_ it, is not at all the same as fatigue as manifested in the
body. If we were to make two curves, the one showing the advancement of
the _feeling_ of fatigue, and the other showing the advancement of
impotence on the part of the bodily processes, the two curves would not
at all coincide. Stated another way, fatigue is a complex thing, a
product of ideas, feelings and sensations, and sometimes the ideas
overbalance the sensations and we think we are more tired then we are
objectively. It is this fact that accounts for our too rapid giving up
when we are engaged in hard work.